This invention relates to a cam action, twist lock assembly support for freight containers, more specifically, to a rotatable twist lock assembly which rotates to a vertical position of use for insertion within the hollow supports of a freight container and, when not in use, rotates to a rest position against a flatbed side rail.
Various attempts have been made to provide a twist lock for freight containers, such as U.S. Pat. No. 3,866,970 of the Applicant herein.
The prior art does not disclose a cam action, downward movement of a twist lock assembly for locking a freight container into securely in place by means of a locking support, which support is also foldable, rotatably against a flatbed trailer side rail support for easy carrying. In the present invention, one feature includes a cam follower, integral with a twist lock locking cone, which cam follower slides down along a cam surface, when the direction of the twist lock locking cone rotates 90 degrees to a locking position, within the hollow supports of a container.
Furthermore, for convenience and safety reasons, another feature of the twist lock assembly is found in that the twist lock assembly is foldable away into a position of non-use against a standard side rail of a flatbed trailer.
Previous attempts to provide a twist lock assembly have provided an assembly leaving a gap of space of approximately 5/16" between the bottom of a locking cone and the surface over which the locking cone rotates. The gap is undesirable, since it results in considerable vibrating of the freight container, resulting in potential damage to the shipping contents and the container support itself.
In addition, various attempts have been made with respect to a twist lock structure which can be folded away in a position of non-use. However, such fold away locking assemblies require extensive structural modifications to the flatbed trailer.
Furthermore, the prior art twist lock assemblies do not describe a smooth locking mechanism, with a locking cone which moves in a rotatable manner following a cam follower down a cam surface as the present invention provides.
The present invention improves upon the prior art by providing not only a cam action twist lock assembly, but also a rotatable foldaway locking assembly which is easily stored away when not in use within the outer dimensional limits of the flatbed trailer. The present invention provides stability by moving the locking cone, and a handle for the locking cone, downwardly along a curved cam surface to provide stability when locking the locking cone in place within the hollow container support housing.